Nanoscale probes, sometimes referred to as nano-probes or nanoscale tips, play a key role in modern technology. For example, a scanning probe microscope (SPM), which is used for detecting the electrical, optical or magnetic characters of a target sample, relies on nanoscale probes to detect and analyze the surface of such target sample. Nanoscale probes are also used for other applications such as miniature emitters of electrons, ion beams, point contacts in conductance measurements, and so on.
The radius of a nanoscale probe is generally measured by nano-meters. Consequently, a scanning electron microscope (SEM) is applied to help identify the profiles of the nanoscale probe. Such profiles include radius of curvature (ROC), length, aspect ratio, surface roughness, and taper angle. Different profiles of nanoscale probes affect the performance of the device being applied to. As an example, with SPM, different profiles of nanoscale probes affect the roughness information, topography information, or contour information of the surface of the target sample that is being detected. To fabricate nanoscale probes with specific profiles, an improved apparatus and method continue to be sought.